Mechanical silent tappet



Jan. 10, 1950' c. L. STANCLIFF MECHANICAL SILENT TAPPET 5 She'ets-Sheet1 Filed July 17, 1945 INVENTOR CL/FTON L. SZZINCLIFF @MEEEE ATTORNEYSJan. 10, 1950 c. L. STANCLIFF 2,493,783

MECHANICAL SILENT TAPPET Filed July 17, 1945 3 Sheets-Sheet 2 INVENTORCZ/Fra/v L. Sigma/FF M, M ATTORNEYS of the two tines of the fork isequal to the distance between the inner surfaces of the grooves 2|. Thispermits the forked end of the arm 22 to be slid into place in thegrooves 2I and the grooves will prevent longitudinal movement of the armalong the shank 9 and will also hold the arm against angular movementwith respect to the shank. Figure 2 shows the arm I4 provided with aplurality of openings 24 and the arm 22 provided with a, plurality ofopenings 25. A coil spring 26 has its ends received in any one of thedesired openings 24 and 25.

The structure is such that the silent tappet can be screwed into thevalve lifter D in place of the usual tappet. If there is insufficientspace for the arm 22 to clear the adjacent portion of the engine block,the arm can be temporarily disconnected from the shank and then theshank can be screwed down into the recess 8. When the desired positionis reached, the arm 22 can have its forked end connected to the shankand then the spring 26 can connect the two arms I4 and 22 together. Ininstalling the silent tappet, the shank 9 is screwed down until thecover I2 clears the valve stem 3 when the valve is seated.

To adjust the tappet for running conditions of the motor, a gage havinga thickness between six to ten-thousandths of an inch is placed betweenthe tappet cover I2 and the end of the valve stem 3. The tappet shank 9is now screwed upwardly in the valve lifter D until the pressure of thecover against the valve stem forces the balls I9 to roll to the bottomsof the spherical recesses I8 and 20, but still the tappet must not exertenough pressure to raise the valve head 4 out of the valve seat I.

The parts are now arranged so that the valve stem can expand from heatcreated by the running of the engine, and this expansion will not raisethe valve from its seat. The spring 26 of course is weaker than thevalve sprin 5. The spring 26 will tend to swing the arms I4 and 22toward each other and this movement will cause the cover to tend torotate with respect to the head II. This rotative movement will causethe balls I9 to lift the cover with respect to the head until the top ofthe cover contacts with the bottom of the valve stem. The fingers I'Ipermit a vertical movement between the head and the cover but preventthe balls I9 from rolling out of the depressions I8 and 20.

The tappet will automatically take care of wear between the top of thecover I2 and the bottom of the valve stem 3. This wear can amount to asmuch as thirty thousandths of an inch and then the tappet can beadjusted to move it closer to the valve stem. Under normal operations itrequires a time period of two or three years to cause wear amounting toabout thirty thousandths of an inch.

l When the valve is seated, the balls I9 will be in the position shownin Figure 3 and the cover I2. will be at its greatest distance :from thehead II. When now the cam C raises the valve lifter D to raise the valvehead off of its seat I, as shown in Figure 4, the pressure of the spring5 on the valve stem 3 will cause the latter to hold the cover I2 againstvertical movement until the cover has retated with respect to the headII after bringing the balls. I 9 to the centers of the sphericaldepressions I-8 and '20. Figure 4 shows this arrangement. The rotatingof the cover I2 with respect to the head II will swing the arm I4 awayfrom the arm 22. This position of the two arms will be maintained untilthe cam 0 permits the valve head 4 to be seated and then should thevalve lifter D move downwardly still further, the coil spring 26 willinstantly come into play and will rotate the cover I2 for causing thecover to remain in continuous contact with the valve stem. There willalways be a metal contact between the valve stem and the tappet and thiswill obviate any possibility of a tappet noise being created by theoperation of the engine.

The spherical recesses I8 and 2!] create a cushioning effect because thewalls of the recesses act on the balls I9 like cams. It is possible tohave the recesses I8 and 20 in the shape of cones or other cam-likesurfaces rather than the spherical depressions.

. In Figure 1 I show a forced feed lubrication system for the valvetappet. An oil pipe 21 conveys oil under pressure to a passa e 28 andthe passage in turn communicates with an annular passage 29 formed inthe outer surface of the valve lifter D. A bore 3|] conveys thelubricant from the passage 29 to the recess 8. The shank 9 has a,central bore 3| that conveys the lubricant into the space between thecover I2 and the head I I. The cover I2 has an opening 32 communicatingwith the space and a film of oil will overlie the top of the cover I2 atall times, this film being fed by oil passing through the opening 32. Afilm of OH will therefore be provided between the bottom of the valvestem 3, and the top of the cover I 2 for lubricating the parts.

In Figure 8 I show a Slightly modified form of lubricating means for thetappet. Here the reservoir 8a in the valve lifter D is filled withgrease. When it is desired to force grease into the space 'between thecover I2 and thehead I I, the lock nut I0 is loosened and the shank 9 isscrewed down into the reservoir a slight distance to force a sulficientquantity of grease from the reservoir into the space between the coverI2 and the head II. The shank 9 is then rotated back to its formerposition and is secured in place by the lock nut [0.

In Figures 5, 6 and 7 I show a modified form of the silent tappet. Inthis form the top of the threaded shank 9a has a head 33 with a top 34provided with a plurality of radially extending grooves 35. The groovestake the place of the spherical depressions I8 in the disc II. Balls 36are held against outward movement b a ring or sleeve 31. This sleeveencloses the peripheral portion of the head 33'and bears against aflange '38. Figure 5 shows the inner ends of the grooves 35 providedwith shoulders to prevent the movement of the balls 36 inwardly towardthe center of the head beyond predetermined points.

A cover 39 takes the place of the cover I2 and has a disc-likeprojection 40 that is receivable within the top of the sleeve 31, seeFigure 6. The cover 39 has a plurality of radially extending grooves 4Isimilar to the grooves 35 and of equal number. The opposed pairs ofgrooves 35 and 4| receive the balls 36. Figure 6 shows the cover 39rotated with respect to the head 33 so that the balls 35 will bedisposed at the portions of the grooves 35 and 4| lying nearest to thetops of the grooves.

Again referring to Figures 5 and 6, it will be noted that a coil spring42 has an end 43 passed thnough an opening 44 provided in a flange 45that is integral with the cover 39. The spring 42 has a portion 46extending from the end 43 and passing through an opening 41 in theflange 38 that registers with the opening 44. The spring 42 then has anarcuate portion 48 that extends through substantially degrees and thenthe spring; has; another portion 49 bent. toparalleli the portion 46;and: to be substantially diametrically opposed thereto. The spring. hasa secondiarcit ate portion 56 that is. disposed above the: flange 65 ofthe cover 3 9 The cover has a proj action. 5 l-= which. is circular inshape and lies within the are cuate portion 50 of thespring. The.opposite end 52 of; the spring issecured to an opening 53 which ispreterably' disposed near the opening, 44.

The: spring. 42: performs a. dual function. In thefirstplace the springholds the. cover 39.- on: the head. 33- while permitting a slightlongitudinal movement betweenthe parts. In: the second placethe springhas a torsional: effect. and tends torotate the cover 39 with respect tothe head 33 so. that thebalis: 36: will. ride up on the arcuatesurfacesof thegrooves 35; and 41-. The devicewhcn' placed: in the valve lifterD, and with thecam. G disposed! at the low point. will have the balls 36in' a position toforce. the cover 39 away from the head 33 to take upany slack between the end. or. the valverstem and the tappe't.. When thecam G lifts the valve head 4', into raised posit-10:1,. the spring 42'will yield to permit the balls 36 to roll to the lowest position. in thegrooves and 41 and this position is shown in Figure 7. Therev is: notappet sound. when this movement occurs, because the; balls will rideover arcuate surfaces in. the grooves. The top of the projection 55'willcontact, with the lower end of the valve stem-13 at allztirnes'lTheshank. 9* has a bore 54 extending longitlrdinally therethrou'gh anddisposed at. the axis of the: shank for carrying a lubricant to. thespace between the head-.33 and cover 39; The cover 331 has a. centralopening 55 for conveying lubricant to: the top of the projection 5L. Afilm of. lubri cant will therefore be formed between the proiection 5tand the bottom of the valve stem.

Although I have shown the device placed be tween. the valve litter andthe lower end? of the valve stem, it. is obvious that the device canoper-- ate iii-connectionwith an. overhead valve: as; well. The devicecan be placed between a. rocker; arnr andithe topot the valve stem inranoverhead valve or it canbe placed. atthe top of a. push rode.

The grooves. 35 and 41 may be made: with: a: milling tool. After thegrooves 35 are: made, the: sleeve 31 is slipped over the head. so as:toretaim the balls 3:6 and rotatably receive the cover 39..

In. Figures 4a and '7- I show the balls: I 9: and 36% lairgtezenough, indiameter ta cause.- them to space the under surfaces of' the covers i2and 39: above: the tops ct theheads t l and 33,.respectively,. when theballs are disposed at the bottomsof therecessz. Thisimeans that theballs will transmit the force required. to lift the valve 4 above itsseat I;.. It is: possible: tomake the balls small. enough. inv dietmeterso that when. they are received at the: bot-- toms. of the recesses; thecovers it and. 3-9; will con.- tact the heads H and 33. In fact a slightclearancabetween the tops of the balls and theupper most portions of therecesses 26 and. 4|. can: be: provided. so that the balls willnot carryany weightwhen the heads I I and 33 are moved up? wardl for lifting thevalve head off from the valveseat. There might be a clearance of. .6012"or .602 for example; between the tops ct the-balls and the highestpoints in the upper recesses. A of oil will lie between the undersideszor the covers- |='2 and t9 and the tops of the heads: H: and; 33-,respectively.

As'thlei heads. H and 33' are. moved. upwardly against the undersurfaces of the covers: l2; andi 35, the covers will rotate with respectto. the:

each other in a spiral: movement rather than. in. a direct longitudinalmovement. This: spiral movement can. be changed in pitch by shaping the:recesses; so that nolsound of metal contacting with metal will; beheard. when; the heads are moved: against the covers. The film. ofoilzbetween the covers andheadswilllubricate thesurfa'oes'to a, pointwhere they will be. practically friction from. In this way the tappet.is really silent operation and guards against any noise being. pro,-duced; when the two surfaces are brought into contact with each other;

I wish. the: present invention to be broad enough in scope to: cover thepoint. of theba-lls spacing the covers and heads: slightly from. eachother when the;ballsareadisposedat the bottoms of their recesses: as.shown in Figures 4 and 7 and. to also cover the complete: contacting ofthe covers with the heads? when the balls are received at the. bottomsof the recesses so that the: balls; will not.- bear any of the weight.when the valve is lifted.

InxFigur'e 1 0 I. show the; device placed. between the. top of a valve;stem 66 and. a rocker arm (it. The? device has; a. head. 62. similar to.the head Ii shown; 1111. Figure 9;. and placed directly on the top ofthe-valverstem so as: to be carried. thereby... The head 62 has a cover63 of the same construction asithefcover t2. Sphericalballszfiiareireceivediin spherical recesses- 65 formed in; the topof the head.and are also received in spherical recesses 66.3 formed inzth'e undersurface of the cover 63-;-

The cover has an arm 61' that is. connectedthereto in the same manner'asth'e arm l4 is'con nected. to the cover: 1-2;. A second arm 68issecuredto the valve stem: Sit so as to project; radially: theretrom.and. a spring. to interconnectsithe free endsof the two: armsso' as toyieldingly urgeztherm toward each other,

The: rocker (ti is mounted. ona rocker shaft tit andonezend I I: of thearm is rounded and.contacts with the top of the cover 63. The other'endioi? the rocker arm carries the usual adjustments'crew 12 and; a lock nut1:31. The adjustment-screw'has a spherical. head 14 that is rockablyreceived. aspherical. recess: I5? formed in the top of a push rod:16..

form of the device is for use on overheadvalves in internal combustionengines and. is to take up any play between the top of the valve'stemz6B and the end H of the rocker arm after the valve spring 1'1. hasreturned the valve toclosed position. The: spring 69 will act on thearms; 61: and 68 to tend to rotate the cover63 with respect to; the head62,. so that the balls 64 will lift the cover above the head so as tocontact with the rocker arm end H at all times. As soon as' the: rockerarm 6i starts to move the valve stem 60;. the initial: movement willmove the cover 63 to ward the head 62 until the two parts contact witheach other, whereupon further swinging movement: of the rocker arm willopen the valve. The device operates in the same Way as: that shown inthe form of the device shown in Figures 1'. and. 5.

Another modified form of the invention. is setforth in Figure 11. Herethe silent tappet is: placed between the push rod 16 and the rocker arm6.1.. The head T8 of the silent tappet is car-- ried by the push rod 16and rotatably supports a. cover" T9 that is similar to the cover 63',and has". a spherical. top portion that is rockably' re-- cei'ved' in a.spherical recess 81 formed in. the rocker arm 6L. The cover T9 has; anarm. 8 21 similar towthe'arm 61 and the head 18 has a lower." portion:8'3 that carries a second arm: 84; which;

heads so that they will" come into contact witlr 7: projects-radiallyfrom the axisoii'thewpushirodilt Aicoil spring 85 interconnects the twoarms. The halls and spherical. recesses provided between the cover 19and the head 18 are the same as that shown in Figure and therefore likereference numerals will be applied to similar parts. At the other end Hof the rocker arm the curved portion of this end contacts directly withthe top of the valve stem 60 in the usual manner. The valve spring 11tends to keep the valve seated at all times. 7 V

The operation of this form of the invention is substantially the same asthat shown in Figure 10.

The spring 85 will swing the arms 82 and B4 toward'each other forlifting the cover 19 above the head 18 and keeping the spherical portion80 seated in thespherical recess 8| at all times. When the push rod 16is actuated for opening the valve 60, the initial movement will roll theballs 64 to the centers of the recesses 65 and 66 and this will permitthe cover 19 to contact with the head 18. Further upward movement of thepush rod 16 will now rock the rocker arm BI and open the valve. Therewill be no mechanical sound between the metallic surfaces during theopening of the valve because the spherical portion 80 will be held incontact with the wall of the spherical recess 8| continuously.

In Figure 9, I show how the cover 12 can contact with the head H duringthe lifting of the valve stem B by the tappet. The balls I9 in thisinstance are slightly less in diameter than the combined heights of thesuperimposed recesses I 8 and 20. Theforms of the devices shown inFigures 1 to 8, inclusive, can operate in this manner if desired. Thestructural feature of having the head and cover contact with oneanother, and thus free the balls from carrying the thrust during theunseating of the valve, will be covered in my copending application,Serial No. 677,552, filed June 18, 1946, entitled Mechanical silenttappet.

I claim:

1. The combination with a. cam-actuated valve lifter, a valve stem, anda valve spring, of a silent tappet carried by the lifter and having acircular head with cam-shaped recesses therein, balls rollably receivedin the recesses, a member rotatably enclosing the circular head andhaving camshaped recesses registering with said first-named recesses andreceiving the tops of the balls, radially extending arms fixed to thehead and member, respectively, the outer ends of the arms being,normally spaced from each other, spring means interconnecting the freeends of the arms for rotating the member on the head for causing theballs to roll to the more shallow portions of the recesses and move themember into contact with the valve stem end, said spring means yieldingwhen the valve lifter moves to lift the Valve and permitting the ballsto roll to the bottoms of the recesses so that the balls will carry thethrust of the valve lifter during the lifting movement.

2. The combination with a cam-actuated valve lifter, a valve stem, and avalve spring, of a silent tappet carried by the lifter and having acircular head with cam-shaped recesses therein, balls rollably receivedin the recesses, a member rotatably enclosing the circular head andhaving camshaped recesses registering with the said first-- namedrecesses and receiving the tops of the balls, spring means for rotatingthe member on the head for causing the balls to roll to the more shallowportions of the recesses and move the member into contact with the valvestem end, said spring means yielding when the valve lifter moves to liftthe valve and permitting the balls to roll to the bottoms of therecesses so that the balls will carry the thrust of the valve lifterduring the lifting movement, said spring means including an armoperatively connected to the head, a second arm swung by the member, anda spring interconnecting the. arms.

13. A silent tappet comprising a shank with a circular head havingspherical recesses in its top and arranged around the center of thehead, a cover having a circular flange rotatably receiving the head andhaving spherical recesses registering with the first-named recesses,balls rollably mounted in the recesses and being of a size to space thecover a slight distance from the head when the balls are disposed at thebottoms of the recesses, the recesses being of a size to cause the ballsto tend to roll to the tops of the recesses when the cover is rotatedwith respect to the head, and spring means disposed exterior of the headand cover for rotating the cover on the head for causing the balls tomove the cover away from the head.

4. A silent tappet comprising a shank with a circular head havingspherical recesses in its top and arranged around the center of thehead, a cover having a circular flange rotatably receiving the head andhaving spherical recesses registering with the first-named recesses,balls rollably mounted in the recesses and being of a size to space thecover a slight distance from the head when the balls are disposed at thebottoms'of the recesses, the recesses being of a size to cause the ballsto tend to roll to the tops of the recesses when the cover is rotatedwith respect to the head, and spring means for rotating the cover on thehead for causing the balls to move the cover away from the head, saidflange carrying means engageable with the head for limiting the movementof the cover away from the head so that the balls will always bereceived in the recesses.

5. A silent tappet comprising a shank with a circular head havingspherical recesses in its top and arranged around the center of thehead, a cover having a circular flange rotatably receiving the head andhaving spherical recesses registering with the first-named recesses,balls rollably mounted in the recesses, the recesses being of a size tocause the balls to tend to roll to the tops of the recesses when thecover is rotated with respect to the head, spring means for rotating thecover on the head for causing the balls to move the cover away from thehead, said spring means including an arm having a ring-shaped endrotatably mounted on the shank and bearing against the underside of thehead, said flange having a recess for receiving the arm so that aswinging of, the arm will rotate the cover on the head, said flange alsohaving fingers for holding the ringshaped arm end in place and forlimiting the movement of the cover away from the head, asecond armrigidly secured to the shank and projecting radially therefrom, and acoil spring interconnecting the arms for urging them toward each otherfor tending to rotate the cover for rolling the balls up the sphericalinclines of the recesses for moving the cover away from the head. ..6. Asilent tappet comprising a shank with a circular head having sphericalrecesses in its top and arranged around the center of the head, a coverhaving a circular flange rotatably receiving the head and havingspherical recesses registering with the first-named recesses, ballsrollably mounted in the recesses, the recesses being of a size to causethe balls to tend to roll to the tops,

of the recesses when the cover is rotated with respect to the head,spring means for rotating the cover on the head for causing the balls tomove the cover away from the head, a valve lifter for receiving theshank, said shank having a bore extending through the head, means fordelivering a lubricant under pressure to the bore for lubricating theballs, said cover having a bore for permitting the lubricant to flow ontop of the cover, said cover being adapted to have its lubricatedsurface abut a valve stem end.

7. A silent tappet comprising a shank with a circular head havingspherical recesses in its top and arranged around the center of thehead, a cover having a circular flange rotatably receiving the head andhaving spherical recesses registering with the first-named recesses,balls rollably mounted in the recesses, the recesses being of a size tocause the balls to tend to roll to the tops of the recesses when thecover is rotated with respect to the head, spring means for rotating thecover on the head for causing the balls to move the cover away from thehead, a valve lifter having a reservoir for receiving lubricant, saidshank being receivable in the reservoir for closing it, said shankhaving a central bore communicating with the reservoir and with thespace between the head and cover, said shank when moved into thereservoir causing lubricant to be forced through the bore forlubricating the balls.

8. A silent tappet comprising a shank with a circular head and anannular flange, said head having radially extending semi-cylindricalrecesses, a cover having a circular portion and an annular flange, thecircular portion having radially extending semi-cylindrical recessesregistering with said first-named recesses, balls placed in theregistering recesses, a sleeve enclosing the head and circular portion,and spring means disposed exterior of the head and cover for maintainingthe cover in place and connected to the flanges for tending to rotatethe cover with respect to the head for causing the balls to roll towardthe rims of the recesses for moving the cover away from the head.

9. In a silent tappet; a head having cam grooves therein; balls placedin the grooves and being REFERENCES CITED The following references areof record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,442,698 Page Jan. 16, 19231,631,563 Titus June 7, 1927 1,663,345 Lievre Mar. 20, 1928 1,790,999Perkins Feb. 3, 1931 1,915,586 Williams June 27, 1933 2,066,976 HolmesJan. 5, 1937 2,234,718 Anglada Mar. 11, 1941 FOREIGN PATENTS NumberCountry Date 1,199 Great Britain Jan. 21, 1905

